What is pneumatic?
Pneumatic means “powered by compressed air”. A pneumatic system converts air pressure into motion or force — as opposed to hydraulic (oil under pressure), electric (current) or hand operated.
A compressor squeezes air into a receiver; hoses carry it to the tool or cylinder, where its expansion does the work. On site the usual working pressure for hand tools is in the order of 6 to 8 bar.
Where you meet pneumatics in construction
- Staplers and nail guns. The standard tool for roof sheathing, battens, floorboards and scaffold boards. Fast, light in the hand and with consistent drive depth.
- Breakers and hammer drills. Large air breakers deliver more impact energy than a comparable electric machine and can run continuously.
- Paint and mortar spraying. Spray plaster, spray gypsum and facade coatings are almost always atomised or conveyed pneumatically.
- Sprayed concrete (shotcrete). Dry mortar is blown along a hose by compressed air to the nozzle, where it is mixed with water.
- Pneumatic conveying of granular materials: cement, aggregate and loose-fill insulation are blown by air pressure from a tanker into a silo or a cavity.
- Pneumatic structures: ETFE air cushion roofs and air-supported halls, where a slight pressure difference holds the structure in shape.
Pneumatic versus hydraulic versus battery
| Pneumatic | Hydraulic | Battery/electric | |
|---|---|---|---|
| Force per unit size | Moderate | Very high | Moderate |
| Tool weight | Low | High | Medium |
| Continuous duty | Yes | Yes | Limited (heat, battery) |
| Support equipment | Compressor + hose | Power pack + hoses | None |
| Leaks | Air, clean | Oil, polluting | n/a |
Compressed air is safe in damp and explosive atmospheres because there are no sparks or hot parts, and a leak is not polluting. Against that, it is energetically inefficient: much of the electrical energy put in is lost as heat during compression.
Practical points
- Water out of the air. Compression produces condensate. Drain the receiver regularly and fit a water separator; water in the tool means rust and poor operation.
- Hose bore and length. A hose that is too narrow or too long causes pressure loss; the tool then runs slowly and fails to drive fully.
- Lubrication. Much air tooling needs oil, via an in-line lubricator or a few drops at the coupling.
- Hearing protection. Air tools and the compressor itself produce high noise levels; hearing protection is not optional.
Related terms
- Compressor
- Hydraulic
- Plastic
- Acrylic
- Render
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